Mertens' Water Monitor

Varanus mertensi

Mertens' Water Monitor is a big lizard that loves to swim! It has a long tail and can be found near water. These lizards are great at catching fish and other tasty treats in the water.

Habitat: Wetlands

Appearance

The Mertens' Water Monitor has a dark grey to blackish-brown body with numerous yellow or cream spots that often form ocelli. Its underside is pale yellow. It features a distinctive flattened snout with nostrils positioned on top, aiding its aquatic lifestyle.

KingdomAnimaliaPhylumChordataClassSquamataOrderLacertiliaFamilyVaranidaeGenusVaranus

Mertens' Water Monitor

Interesting facts

Baby monitors have much brighter patterns than adults, helping them blend into their surroundings!

These lizards can walk along the bottom of rivers and lakes, exploring silently!

They spend most of their entire lives splashing, hunting, and relaxing in freshwater!

They use their forked tongue to 'smell' chemicals in water, finding hidden snacks!

Special abilities

Mertens' Water Monitor has clear vision both in air and water, allowing them to spot prey above and below the surface.

Mertens' Water Monitor can powerfully propel itself with a strong, laterally flattened tail that helps them chase fish.

Mertens' Water Monitor can breathe with just its nostrils above water because they are placed high on its flattened snout.

Measurements & details

Length: 80-130 cm
Weight: 2-5 kg
Lifespan: 10-15 years
Top Speed: 15 km/h
Swim Speed: 15 km/h
Clutch Size: 6-18
Incubation: 190-210 days
Maximum Depth: 10 m

Diet & Feeding

A speedy swimmer that eats fish, frogs, and other small aquatic creatures in northern Australia's waterways.

Age differences: Juveniles mostly eat insects and very small aquatic prey, while adults consume larger fish and frogs.

Primary Foods

Fish
Frogs
Crayfish
Water insects
Small reptiles

Foraging Method

Pursuit

Ecological connections

eats

Green Tree Frog

Litoria caerulea

A common frog species preyed upon.

eats

Eastern Rainbowfish

Melanotaenia splendida

A widespread fish often hunted.

eaten by

Saltwater Crocodile

Crocodylus porosus

Larger crocodiles can prey on monitors.

Traits

Webbed Feet

Characterized by having toes connected by a membrane, typically aiding in swimming.

Solitary

Solitary animals live alone for most of their lives, only interacting with others for mating or parental care.

Piscivorous

Piscivorous organisms are animals that primarily subsist on a diet of fish.

Ambush Predator

An ambush predator hunts by patiently waiting and concealing itself, then launching a sudden attack when unsuspecting prey comes within range.

Wetland

This habitat trait identifies species found in wetlands, which are areas of land saturated with water, either permanently or seasonally, including marshes, swamps, and bogs.